I tried to implement a item that can be used multiple time in a crafting recipe, however, each usage will cause the item to lose 1 durability.

In my particular example, I made a hammer that can be used with four coal to craft compacted coal, I attempted to implement this by overriding the getContainerItem method, where I basically applied one damage to the item, then returned the damaged item. To my knowledge this should make the damaged item as the container, and that will remain on the crafting grid after crafting is completed, however in practice this implementation doesn't work, and the hammer will still be consumed along with the other ingredients.

This is my current code for the WoodenHammer class (excluding the imports):

public class ItemWoodenHammer extends Item {

    public ItemWoodenHammer(Properties pProperties) {
        super(pProperties.durability(60));

    }

    @Override
    public boolean isDamageable(ItemStack stack) {
        return true;
    }

    @Override
    public boolean hasContainerItem(ItemStack stack) {
        return true;
    }



    @Override
    public ItemStack getContainerItem(ItemStack itemStack) {
        itemStack.hurt(1, new Random(), null);
        System.out.println("hammer max durability:" + itemStack.getMaxDamage());
        System.out.println("hammer's current state: " + itemStack);
        return itemStack;
    }

}

Here's the compactcoalfromwoodenhammer.json for the recipe:

{
  "type": "minecraft:crafting_shapeless",
  "ingredients": [
    {
      "item": "ornithophobia:wooden_hammer"
    },
    {
      "item": "minecraft:coal"
    },
    {
      "item": "minecraft:coal"
    },
    {
      "item": "minecraft:coal"
    },
    {
      "item": "minecraft:coal"
    }
  ],
  "result": {
    "item": "ornithophobia:compacted_coal"
  }
}

As you may see I tried to print out the hammer's max durability and the current state, since I initially suspect either I messed up assigning the durability to the hammer or I messed up with the item hurt method, but the print output suggest that hammer's max durability is 60, suggesting it's applied correctly, and that 1 damage was inflicted on the itemStack when crafting occurred. In addition, the print outputted at all suggest that the getContainerItem method is triggering when the crafting happened, yet still, nothing is left behind on the crafting grid, suggesting that the returning part was somehow broken, and yet I can't figure out how. 

I am just starting out modding with forge literally two days ago so my implementation of these functions are probably pretty dumb and I probably made some real silly mistake, but I have been trying to debug this for hours and it's seriously giving me a brain aneurysm. Any amount of help/insight is very much appreciated, huge thanks in advance.

Edited November 4, 20222 yr by RuthlessNail
editing the title to reflect that the problem have been solved

I don't think its documentated, but you need to return a new ItemStack not the original.

Something like: 

    @Override
    public ItemStack getContainerItem(ItemStack itemStack) {
        // Copy the original
        var result = itemStack.copy();
        // Damage it
        result.hurtAndBreak(1, ForgeHooks.getCraftingPlayer(), player -> {
            if (player != null) {
                player.level.playSound(null, player.getX(), player.getY(), player.getZ(), ITEM_BREAK, player.getSoundSource(), 1.0f, 1.0f);
            }
        });
        return result;
    }

 

Edited November 4, 20222 yr by warjort

17 minutes ago, warjort said:

I don't think its documentated, but you need to return a new ItemStack not the original.

Something like: 

    @Override
    public ItemStack getContainerItem(ItemStack itemStack) {
        // Copy the original
        var result = itemStack.copy();
        // Damage it
        result.hurtAndBreak(1, ForgeHooks.getCraftingPlayer(), player -> {
            if (player != null) {
                player.level.playSound(null, player.getX(), player.getY(), player.getZ(), ITEM_BREAK, player.getSoundSource(), 1.0f, 1.0f);
            }
        });
        return result;
    }

 

Thank you sir, you are a literal life-saver. This works flawlessly.